The problem of pollution from automobiles is now very well recognized, and national, state and local laws have been passed requiring corrections. Attempts at solving the problem of pollution by cars have steadily been accompanied by decreasing the performance of the vehicle, making it harder to start and hard to stop when ignition is turned off due to auto-ignition, more critical to keep in adjustment and less drivable, less powerful, and less economical. A vast amount of money has been spent in many, many projects by the automobile companies and others, but the automobile companies are having great difficulties finding solutions that can meet the requirements established by the laws. Considerable work has been done on catalytic converters in the exhaust system but it all shows that to date there is no successful catalytic material that has reasonable life which can exist without eliminating the lead in the fuel. It therefore becomes an essential ingredient of any catalytic system that is to be successful that it must first of all eliminate the lead from the fuel. Even a small amount of lead has a very serious effect upon the life of the catalytic converter. Past solutions to this problem of emission control are also in general very expensive and generally do not lend themselves to application to already existent cars in the field. Another problem common with present cars is their tendency to pre-ignite and to afterfire when the ignition is cut off. They continue to cycle, which is called auto-ignition or dieseling. This is caused by a local hot spot in the combustion chamber which is hot enough to cause ignition of the fuel-air mixture and in advanced state is moving steadily ahead in ignition cycle after cycle, getting the combustion chamber hotter and hotter. When present high compression ratio engines with high spark advance used are used with no lead low octane fuel, they invariably go into a condition of pre-ignition or auto-ignition within their operating cycle. In an attempt to eliminate this problem, spark advance is normally retarded very severely and in new engines the cylinders and/or pistons are changed to lower compression ratio from 10.5 to approximately 8 to 8.5. These both seriously hurt combustion efficiency and so increase exhaust emissions, carbon monoxide and unburned hydrocarbons, making them much worse, and also seriously hurt economy and engine performance. Solutions proposed so far do not lend themselves to application to already existent vehicles in the field. This is a serious problem as any successful solution to the problem must cope with the very large number of cars already existent in the field and do so easily. In California laws have been passed requiring an emission control device to be applied to all 1955 to 1970 cars.
It has previously been proposed to inject water and steam into the induction systems of reciprocating piston internal combustion engines.
The prior art proposals for the injection of water or stream can be dividable primarily into two areas. The water or steam was injected either directly into the vacuum in the inlet manifold or was injected as a part of the throttle linkage speed control. In either case the prior art fluid injection systems did not produce the injection of sufficient amounts of fluid over the full engine operating range and/or gave excessive amounts under some conditions and did not supply fluid as needed.
In the vacuum control system the fluid was not injected in correct amounts at idle (normally being too much) and at full load was quite insufficient.
In both the former vacuum control and the throttle linkage control systems little or no fluid was injected during acceleration at full throttle under full load from low speed. This is precisely the time when the maximum amount of fluid injection is needed.